Chair Assembly

ABSTRACT

A seating unit includes a seat assembly adapted to support a seated user thereon, a back assembly extending upwardly from the seat assembly and adapted to support a seated user, and a headrest assembly adapted to support a head of a seated user. The headrest assembly includes a frame assembly having a pair of vertically spaced frame portions and a pair of horizontally spaced frame portions, wherein the frame portions cooperate to form an open space therebetween, and wherein at least one of the frame portions includes a plurality of first alignment features, and a thermoplastic elastomeric cover member stretched between at least one of the pair of vertically spaced frame portions and the pair of horizontally spaced frame portions, wherein the cover member includes a plurality of second alignment features that cooperate with the first alignment features to align the cover member with the frame assembly.

BACKGROUND OF THE INVENTION

The present invention relates to a chair assembly, and in particular toan office chair assembly comprising a vertically adjustable,articulating headrest assembly.

BRIEF SUMMARY OF THE INVENTION

One aspect of the present invention is to provide a seating unitcomprising a seat assembly adapted to support a seated user thereon, aback assembly extending upwardly from the seat assembly and adapted tosupport a seated user, and a headrest assembly adapted to support a headof a seated user. The headrest assembly comprises a frame assemblyincluding a pair of vertically spaced frame portions and a pair ofhorizontally spaced frame portions, wherein the frame portions cooperateto form an open space therebetween, and wherein at least one of theframe portions includes a plurality of first alignment features, and athermoplastic elastomeric cover member stretched between at least one ofthe pair of vertically spaced frame portions and the pair ofhorizontally spaced frame portions, wherein the cover member includes aplurality of second alignment features that cooperate with the firstalignment features to align a cover member with the frame assembly.

These and other features and advantages of the present invention will befurther understood and appreciated by those skilled in the art byreference to the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a chair assembly embodying thepresent invention;

FIG. 2 is a rear perspective view of the chair assembly;

FIG. 3 is a side elevational view of the chair assembly showing thechair assembly in a lowered position and in a raised position in dashedline, and a seat assembly in a retracted position and an extendedposition in dashed line;

FIG. 4 is a side elevational view of the chair assembly showing thechair assembly in an upright position and in a reclined position indashed line;

FIG. 5 is an exploded view of the seat assembly;

FIG. 6 is an enlarged perspective view of the chair assembly with aportion of the seat assembly removed to illustrate a spring supportassembly;

FIG. 7 is a front perspective view of a back assembly;

FIG. 8 is a side elevational view of the back assembly;

FIG. 9 a is an exploded front perspective view of the back assembly;

FIG. 9 b is an exploded rear perspective view of the back assembly;

FIG. 10 is an enlarged perspective view of an area 10, FIG. 9 a;

FIG. 11 is an enlarged perspective view of an area 11, FIG. 2;

FIG. 12 is a cross-sectional view of an upper back pivot assembly takenalong the line XII-XII, FIG. 7;

FIG. 13 a is an exploded rear perspective view of the upper back pivotassembly;

FIG. 13 b is an exploded front perspective view of the upper back pivotassembly;

FIG. 14 is an enlarged perspective view of the area 14, FIG. 9 b;

FIG. 15 a is an enlarged perspective view of a comfort member and alumbar assembly;

FIG. 15 b is a rear perspective view of the comfort member and thelumbar assembly;

FIG. 16 a is a front perspective view of a pawl member;

FIG. 16 b is a rear perspective view of the pawl member;

FIG. 17 is a partial cross-sectional perspective view along the lineXVIII-XVIII, FIG. 15 b;

FIG. 18 is a perspective view of an alternative embodiment of the chairassembly including a headrest assembly;

FIG. 19 is a side elevational view of the alternative embodiment of thechair assembly, showing the headrest at lowered and raised positions;

FIG. 20 is a side elevational view showing the headrest at a forward anda rearward articulated position;

FIG. 21 is an exploded front perspective view of the back assembly;

FIG. 22 is an exploded rear perspective view of the back assembly;

FIG. 23 is an exploded perspective view of the headrest assembly;

FIG. 24 is a cross-sectional view of the headrest assembly taken alongthe line XXIV-XXIV, FIG. 21;

FIG. 25 is a cross-sectional view of the headrest assembly taken alongthe line XXV-XXV, FIG. 21;

FIG. 26 is a perspective view of the alternative embodiment of the chairassembly;

FIG. 27 is a front elevational view of the alternative embodiment of thechair assembly;

FIG. 28 is a first side elevational view of the alternative embodimentof the chair assembly;

FIG. 29 is a second side elevational view of the alternative embodimentof the chair assembly;

FIG. 30 is a rear elevational view of the alternative embodiment of thechair assembly;

FIG. 31 is a top plan view of the alternative embodiment of the chairassembly; and

FIG. 32 is a bottom plan view of the alternative embodiment of the chairassembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For purposes of description herein, the terms “upper,” “lower,” “right,”“left,” “rear,” “front,” “vertical,” “horizontal,” and derivativesthereof shall relate to the invention as oriented in FIGS. 1 and 2.However, it is to be understood that the invention may assume variousalternative orientations and step sequences, except where expresslyspecified to the contrary. It is also to be understood that the specificdevices and processes illustrated in the attached drawings, anddescribed in the following specification are exemplary embodiments ofthe inventive concepts defined in the appended claims. Hence, specificdimensions and other physical characteristics relating to theembodiments disclosed herein are not to be considered as limiting,unless the claims expressly state otherwise.

The reference numeral 10 (FIGS. 1 and 2) generally designates a chairassembly embodying the present invention. In the illustrated example,the chair assembly 10 includes a castered base assembly 12 abutting asupporting floor surface 13, a control or support assembly 14 supportedby the castered base assembly 12, a seat assembly 16 and back assembly18 each operably coupled with the control assembly 14, and a pair of armassemblies 20. The control assembly 14 (FIG. 3) is operably coupled tothe base assembly 12 such that the seat assembly 16, the back assembly18 and the arm assemblies 20 may be vertically adjusted between a fullylowered position A and a fully raised position B, and pivotable about avertical axis 21 in a direction 22. The seat assembly 16 is operablycoupled to the control assembly 14 such that the seat assembly 16 islongitudinally adjustable with respect to the control assembly 14between a fully retracted position C and a fully extended position D.The seat assembly 16 and the back assembly 18 are operably coupled withthe control assembly 14 and with one another such that the back assembly18 is movable between a fully upright position E and a fully reclinedposition F, and further such that the seat assembly 16 is movablebetween a fully upright position G and a fully reclined position Hcorresponding to the fully upright position E and the fully reclinedposition F of the back assembly 18.

The base assembly 12 includes a plurality of pedestal arms radiallyextending and spaced about a hollow central column 26 that receives apneumatic cylinder 28 therein. Each pedestal arm 24 is supported abovethe floor surface 13 by an associated caster assembly 30. Although thebase assembly 12 is illustrated as including a multiple-arm pedestalassembly, it is noted that other suitable supporting structures maybeutilized, including but not limited to fixed columns, multiple legarrangements, vehicle seat support assemblies, and the like.

The seat assembly 16 (FIG. 5) includes a relatively rigid seat supportplate 32 having a forward edge 34, a rearward edge 36, and a pair ofC-shaped guide rails 38 defining the side edges of the seat supportplate 32 and extending between the forward edge 34 and the rearward edge36. The seat assembly 16 further includes a flexibly resilient outerseat shell 40 having a pair of upwardly turned side portions 42 and anupwardly turned rear portion 44 that cooperate to form an upwardlydisposed generally concave shape. The seat shell 40 is comprised of arelatively flexible material such as thermoplastic elastomer (TPE). Inassembly, the outer seat shell 40 is secured and sandwiched between theseat support plate 32 and a plastic, flexibly resilient seat pan 46which is secured to the seat support plate 32 by a plurality ofmechanical fasteners. The seat pan 46 includes a forward edge 48, arearward edge 50, side edges 52 extending between the forward edge 48and the rearward edge 50, a top surface 54 and a bottom surface 56 thatcooperate to form an upwardly disposed generally concave shape. In theillustrated example, the seat pan 46 includes a plurality oflongitudinally extending slots 58 extending forwardly from the rearwardedge 50. The slots 58 cooperate to define a plurality of fingers 60therebetween, each finger 60 being individually flexibly resilient. Theseat pan 46 further includes a plurality of laterally oriented,elongated apertures 62 located proximate the forward edge 48. Theapertures 62 cooperate to increase the overall flexibility of the seatpan 46 in the area thereof, and specifically allow a forward portion 64of the seat pan 46 to flex in a vertical direction 66 with respect to arearward portion 68 of the seat pan 46, as discussed further below. Theseat assembly 16 further includes a foam cushion member 70 that restsupon the top surface 54 of the seat pan 46 and is cradled within theouter seat shell 40, and a fabric seat cover 72 (FIGS. 1 and 2) and anupper surface 76 of the cushion members 70. The seat assembly 16 furtherincludes a spring support assembly 78 (FIGS. 5 and 6) adapted toflexibly support the forward portion 64 of the seat pan 46 for flexurein the vertical direction 66. In the illustrated example, the springsupport assembly 78 includes a support housing 80 comprising a foam andhaving side portions 82 defining an upwardly concave arcuate shape. Thespring support assembly 78 further includes a relatively rigidattachment member 84 that extends laterally between the side portions 82of the support housing 80 and is located between the support housing 80and the forward portion 64 of the seat pan 46. A plurality of mechanicalfasteners 86 secure the support housing 80 and the attachment member 84to the forward portion 64 of the seat pan 46. The spring supportassembly 78 further includes a pair of cantilever springs 88 each havinga distal end 90 received through a corresponding aperture 92 of theattachment member 84, and a proximate end 94 secured to the seat supportplate 32 such that the distal end 90 of each cantilever spring 88 mayflex in the vertical direction 66. A pair of linear bearings 96 arefixedly attached to the attachment member 84 and aligned with theapertures 92 thereof, such that the linear bearing 96 slidably receivesthe distal ends 90 of a corresponding cantilever springs 88. Inoperation, the cantilever springs 88 cooperate to allow the forwardportion 64 of the seat pan 46, and more generally the entire forwardportion of seat assembly 16 to flex in the vertical direction 66 when aseated user rotates forward on the seat assembly 16 and exerts adownward force on the forward edge thereof.

The back assembly 18 (FIGS. 7-9B) includes a back frame assembly 98 anda back support assembly 99 supported thereby. The back frame assembly 98is generally comprised of a substantially rigid material such as metal,and includes a laterally extending top frame portion 100, a laterallyextending bottom frame portion 102, and a pair of curved side frameportion 104 extending between the top frame portion 100 and the bottomframe portion 102 and cooperating therewith to define an opening 106having a relatively large upward dimension 108 and a relatively narrowlower dimension 110.

The back assembly 18 further includes a flexibly resilient, plastic backshell 112 having an upper portion 114, a lower portion 116, a pair ofside edges 118 extending between the upper portion 114 and a lowerportion 116, a forwardly facing surface 120 and a rearwardly facingsurface 122, wherein the width of the upper portion 114 is generallygreater than the width of the lower portion 116, and the lower portion116 is downwardly tapered to generally follow the rear elevationalconfiguration of the frame assembly 98. A lower reinforcement member 115attaches to hooks 117 (FIG. 9A) of lower portion 116 of back shell 112.Reinforcement member 115 includes a plurality of protrusions 113 thatengage reinforcement ribs 134 to prevent side-to-side movement of lowerreinforcement member 115 relative to back shell 112. As discussed below,reinforcement member 115 pivotably interconnects back control link 342(FIG. 26) to lower portion 116 of back shell 112 at pivot points or axis346.

The back shell 112 also includes a plurality of integrally molded,forwardly and upwardly extending hooks 124 (FIG. 10) spaced about theperiphery of the upper portion 114 thereof. An intermediate or lumbarportion 126 is located vertically between the upper portion 114 and thelower portion 116 of the back shell 112, and includes a plurality oflaterally extending slots 128 that cooperate to form a plurality oflaterally extending ribs 130 located therebetween. The slots 128cooperate to provide additional flexure to the back shell 112 in thelocation thereof. Pairings of lateral ribs 130 are coupled by verticallyextending ribs 132 integrally formed therewith and located at anapproximate lateral midpoint thereof. The vertical ribs 132 function totie the lateral ribs 130 together and reduce vertical spreadingtherebetween as the back shell 112 is flexed at the intermediate portion126 thereof when the back assembly 18 is moved from the upright positionE to the reclined position F, as described below. The back shell 112further includes a plurality of laterally-spaced reinforcement ribs 134extending longitudinally along the vertical length of the back shell 112between the lower portion 116 and the intermediate portion 126. It isnoted that the depth of each of the ribs increases the further alongeach of the ribs 134 from the intermediate portion 126, such that theoverall rigidity of the back shell 112 increases along the length of theribs from the intermediate portion 126 towards the lower portion 116.

The back shell 112 further includes a pair of rearwardly extending,integrally molded pivot bosses 138 forming part an upper back pivotassembly 140. The back pivot assembly 140 (FIGS. 11-13 b) includes thepivot bosses 138 of the back shell 112, a pair of shroud members 142that encompass respective pivot bosses 138, a race member 144, and amechanical fastening assembly 146. Each pivot boss 138 includes a pairof side walls 148 and a rearwardly-facing concave seating surface 150having a vertically elongated pivot slot 152 extending therethrough.Each shroud member 142 is shaped so as to closely house thecorresponding pivot boss 138, and includes a plurality of side walls 154corresponding to side walls 148, and a rearwardly-facing concave bearingsurface 156 that includes a vertically elongated slot pivot slot 143extending therethrough, and which is adapted to align with the slot 152of a corresponding pivot boss 138. The race member 144 includes a centerportion 158 extending laterally along and abutting the top frame portion100 of the back frame assembly 98, and a pair of arcuately-shapedbearing surfaces 160 located at the ends thereof. Specifically, thecenter portion 158 includes a first portion 162, and a second portion164, wherein the first portion 162 abuts a front surface of the topframe portion 100 and second portion 164 abuts a top surface of the topframe portion 100. Each bearing surface 160 includes an aperture 166extending therethrough and which aligns with a corresponding boss member168 integral with the back frame assembly 98.

In assembly, the shroud members 142 are positioned about thecorresponding pivot bosses 138 of the back shell 112 and operablypositioned between the back shell 112 and race member 144 such that thebearing surface 156 is sandwiched between the seating surface 150 of acorresponding pivot boss 138 and a bearing surface 160. The mechanicalfastening assemblies 146 each include a bolt 172 that secures a roundedabutment surface 174 of the bearing washer 176 in sliding engagementwith an inner surface 178 of the corresponding pivot boss 138, andthreadably engages the corresponding boss member 168 of the back shell112. In operation, the upper back pivot assembly 140 allows the backsupport assembly 99 to pivot with respect to the back frame assembly ina direction 180 (FIG. 8) about a pivot axis 182 (FIG. 7).

The back support assembly 99 further includes a flexibly resilientcomfort member 184 attached to the back shell 112 and slidablysupporting a lumbar assembly 186. The comfort member 184 includes anupper portion 188, a lower portion 190, a pair of side portions 192, aforward surface 193 and a rearward surface 195, wherein the upperportion 188, the lower portion 190 and the side portions cooperate toform an aperture 194 that receives the lumbar assembly 186 therein. Asbest illustrated in FIGS. 9 b and 14, the comfort member 184 includes aplurality of box-shaped couplers 196 spaced about the periphery of theupper portion 188 and extending rearwardly from the rearward surface195. Each box-shaped coupler 196 includes a pair of side walls 198 and atop wall 200 that cooperate to form an interior space 202. A bar 204extends between the side walls 198 and is spaced from the rearwardsurface 195. In assembly, and as best illustrated in FIG. 12, thecomfort member 184 is secured to the back shell 112 by aligning andvertically inserting the hooks 124 of the back shell 112 into theinterior space 202 of the box-shaped couplers 196 until the hooks 124engage a corresponding bar 204. It is noted that the forward surface 120of the back shell 112 and the rearward surface 195 of the comfort member184 are free from holes or apertures proximate the hooks 124 andbox-shaped couplers 196, thereby providing a smooth forward surface 193and increasing the comfort to a seated user.

The comfort member 184 (FIGS. 15 a and 15 b) includes an integrallymolded, longitudinally extending sleeve 206 extending rearwardly fromthe rearward surface 195 and having a rectangularly-shapedcross-sectional configuration. The lumbar assembly 186 includes aforwardly laterally concave and forwardly vertically convex, flexiblyresilient body portion 208, and an integral support portion 210extending upwardly from the body portion 208. In the illustratedexample, the body portion 208 is shaped such that the body portionvertically tapers along the height thereof so as to generally follow thecontours and shape of the aperture 194 of the comfort member 184. Thesupport portion 210 is slidably received within the sleeve 206 of thecomfort member 184 such that the lumbar assembly 186 is verticallyadjustable with respect to the remainder of the back support assembly 99between a fully lowered position I and a fully raised position J. A pawlmember 212 selectively engages a plurality of apertures 214 spaced alongthe length of support portion 210, thereby releasably securing thelumbar assembly 186 at selected vertical positions between the fullylowered position I and the fully raised position J. The pawl member 212(FIGS. 16 a and 16 b) includes a housing portion 216 having engagementtabs 218 located at the ends thereof and rearwardly offset from an outersurface 220 of the housing portion 216. A flexibly resilient finger 222is centrally disposed within the housing portion 216 and includes arearwardly-extending pawl 224.

In assembly, the pawl member 212 (FIG. 17) is positioned within anaperture 226 located within the upper portion 188 of the comfort member184 such that the outer surface 220 of the housing portion 216 of thepawl member 212 is coplanar with the forward surface 193 of the comfortmember 184, and such that the engagement tabs 218 of the housing portion216 abut the rearward surface 195 of the comfort member 184. The supportportion 210 of the lumbar assembly 186 is then positioned within thesleeve 206 of the comfort member 184 such that the sleeve 206 isslidable therein and the pawl 224 is selectively engageable with theapertures 214, thereby allowing the user to optimize the position of thelumbar assembly 186 with respect to the overall back support assembly99. Specifically, the body portion 208 of the lumbar assembly 186includes a pair of outwardly extending integral handle portions eachhaving a C-shaped cross-sectional configuration defining a channel 253therein that wraps about and guides along the respective side edge 192of the back shell 112.

In operation, a user adjusts the relative vertical position of thelumbar assembly 186 with respect to the back shell 112 by grasping oneor both of the handle portions 251 and sliding the handle assembly 251along the back shell 184 in a vertical direction. A stop tab 228 isintegrally formed within a distal end 230 and is offset therefrom so asto engage an end wall of the sleeve 206 of the comfort member 184,thereby limiting the vertical downward travel of the support portion 210of the lumbar assembly 186 with respect to the sleeve 206 of the comfortmember 184.

The back assembly 99 further includes a cushion member 252 having anupper portion 254 and a lower portion 256, wherein the lower portion 256tapers along the vertical length thereof to correspond to the overallshape and taper of the back shell 112 and the comfort member 184.

The reference numeral 10 a (FIG. 18) generally designates anotherembodiment of the chair assembly. Since the chair assembly 10 a issimilar to the previously described chair assembly 10, similar partsappearing in FIGS. 1-17 and FIGS. 18-25 respectively are represented bythe same, corresponding reference numeral, except for the suffix “a” inthe numerals of the latter. The chair assembly 10 a is similar to thepreviously described chair assembly 10, with the most notable exceptionbeing the inclusion of a headrest assembly 300 and the reconfigurationof the back assembly 18 a to accommodate the same. As best illustratedin FIGS. 18-20, the headrest assembly is pivotable about a horizontalpivot axis 302 between a rearwardly articulated position K and aforwardly articulated position L, and vertically adjustable between alowered position M and a raised position N.

In the illustrated example, the back assembly 18 a includes a back frameassembly 98 a and a back support assembly 99 a. The back supportassembly 99 a is constructed in a similar manner to the back supportassembly 99, as previously described. The back frame assembly includes aback frame member 304 and a back frame housing 306. The back framemember 304 includes a blade-shaped, laterally extending top frameportion 100 a, a laterally extending bottom frame portion 102 a, and apair of curved side frame portions 104 a extending between the top frameportion 100 a and the bottom frame portion 102 a and cooperatingtherewith to define an opening 106 a. The back frame housing 306 iscoupled to the back frame member 304 via a plurality of mechanicalfasteners (not shown) and is configured so as to define a gap 310therebetween that telescopingly receives the headrest assembly 300therein.

The headrest assembly 300 includes a blade portion 314 that istelescopingly received within the gap 310 and includes a pair ofelastically resilient, forwardly-extending tab members 316 that engagecorresponding, rearwardly-extending ramp members 318 of the back framehousing 306, thereby securing the blade portion 314 of the headrestassembly 300 within the gap 310 and preventing removal of the headrestassembly 300 from the overall chair assembly 10 a. A pair ofoutwardly-opening channels 320 extend along the edges of the bladeportion 314 and track along corresponding track members 322 secured tothe back frame member 304 during vertical adjustment of the headrestassembly 300. The blade portion 314 of the headrest assembly 300 furtherincludes a vertically-extending, forwardly-opening channel 324 thatincludes a plurality of vertically-spaced detents 326 that are engagedby pawls 328 of an engagement member 330 attached to a rear surface ofthe back frame housing 306. The pawls 328 selectively engage the detents326, thereby allowing the headrest assembly 300 to be selectivelyvertically positioned between the lowered position M and the raisedposition N.

As best illustrated in FIG. 23, the headrest assembly 300 furtherincludes a headrest frame 332 covered by a headrest cover 334 held inconnection with the headrest frame 332 by a pair of stays 336 andcovered by an end cover 338. In the illustrated example, the headrestframe 332 includes a laterally-extending top portion 340, alaterally-extending bottom portion 342 vertically spaced from the topportion 340, and a pair of forwardly, arcuately-shaped side portions 344horizontally spaced from one another, extending between the top portion340 and the bottom portion 342 and cooperating therewith to define anopen space 346 therebetween. The headrest cover 334 comprises anelastomeric material and is placed over the open space 346 of theheadrest frame 332 such that the headrest cover 334 is stretched in thelateral direction 348. The outer lateral edges 350 (FIG. 24) of theheadrest cover 334 are sewn to the stays 336 or alternatively secured byan adhesive or other suitable means. The stays 336 are positioned withinoutwardly-opening channels 352 extending along the side portions 344 ofthe headrest cover 334, and secured within the channels 352 by theelastic tension exerted by the headrest cover 334, although otheralternative securing means may be utilized. An outer edge 354 (FIG. 25)of the headrest cover 334 includes a plurality of laterally-spacedapertures 356 that receive hook-shaped tabs 356 of the bottom portion342 of the headrest frame assembly 332 therein, thereby properlyaligning the headrest cover 334 with the headrest frame 332. The endcover 338 is positioned over the bottom portion 342 of the headrestframe 332, thereby concealing the outer edge 354 of the headrest cover334. The end cover 338 is flexibly resilient and includes a plurality oftabs 360 that engage the tabs 358, thereby securing the end cover 338 tothe headrest frame 332. The top portion 340 of the headrest frame 332and the hinge cap 362 are configured similarly to the bottom portion 342of the headrest frame 332 and the end cover 338, respectively, so as toalign, secure and conceal an inner edge 364 of the headrest cover 334. Afriction-locking hinge member 370 is located within the hinge cap 362and engages the hinge cap 362 and a pair of upwardly extending arms 372integral with the blade portion 314, thereby allowing the headrestassembly 300 to be adjusted between the retracted position K and theextended position L.

In the foregoing description, it will be readily appreciated by thoseskilled in the art that modifications may be made to the inventionwithout departing when the concept is disclosed. Such modifications areto be considered as included in the following claims, unless theseclaims by their language expressly state otherwise.

1. A seating unit, comprising: a seat assembly adapted to support aseated user thereon; a back assembly extending upwardly from the seatassembly and adapted to support a seated user; a headrest assemblyadapted to support a head of a seated user, the headrest assemblycomprising: a frame assembly including a pair of vertically spaced frameportions and a pair of horizontally spaced frame portions, wherein theframe portions cooperate to form an open space therebetween, and whereinat least one of the frame portions includes a plurality of firstalignment features; and a thermoplastic elastomeric cover memberstretched between at least one of the pair of vertically spaced frameportions and the pair of horizontally spaced frame portions, wherein thecover member includes a plurality of second alignment features thatcooperate with the first alignment features to align the cover memberwith the frame assembly.
 2. The seating unit of claim 1, wherein thecover member is stretched between the pair of horizontally spaced frameportions.
 3. The seating unit of claim 2, wherein the pair of verticallyspaced frame portions includes the first alignment features.
 4. Theseating unit of claim 3, wherein the first alignment features include atleast one of a plurality of spaced recesses and a plurality of spacedtabs, and wherein the second alignment feature includes the other of theplurality of spaced recesses and the plurality of spaced tabs.
 5. Theseating unit of claim 4, wherein the first alignment features includethe plurality of apertures.
 6. The seating unit of claim 5, wherein thehorizontally spaced frame portions of the headrest each include alongitudinally extending recess, and wherein the cover member is securedwithin the recesses of the frame portions by stays received within therecesses.
 7. The seating unit of claim 6, further including: a supportassembly adapted to support a floor surface.
 8. The seating unit ofclaim 7, wherein the support assembly includes a pedestal assembly and aplurality of castors.
 9. The seating unit of claim 8, furthercomprising: a first cap member secured to the frame assembly such that aportion of the cover member is positioned between the first cap memberand one of the frame portions.
 10. The seating unit of claim 9, furthercomprising: a second cap member secured to the frame assembly oppositethe first cap member such that a portion of the cover member ispositioned between the second cap member and one of the frame portions.11. The seating unit of claim 1, wherein the pair of vertically spacedframe portions includes the first alignment features.
 12. The seatingunit of claim 1, wherein the first alignment features include at leastone of a plurality of spaced recesses and a plurality of spaced tabs,and wherein the second alignment feature includes the other of theplurality of spaced recesses and the plurality of spaced tabs.
 13. Theseating unit of claim 12, wherein the first alignment features includethe plurality of apertures.
 14. The seating unit of claim 1, wherein thehorizontally spaced frame portions of the headrest each include alongitudinally extending recess, and wherein the cover member is securedwithin the recesses of the frame portions by stays received within therecesses.
 15. The seating unit of claim 1, further including: a supportassembly adapted to support a floor surface.
 16. The seating unit ofclaim 15, wherein the support assembly includes a pedestal assembly anda plurality of castors.
 17. The seating unit of claim 1, furthercomprising: a first cap member secured to the frame assembly such that aportion of the cover member is positioned between the first cap memberand one of the frame portions.
 18. The seating unit of claim 17, furthercomprising: a second cap member secured to the frame assembly oppositethe first cap member such that a portion of the cover member ispositioned between the second cap member and one of the frame portions.19. The seat unit of claim 1, wherein the headrest assembly isvertically adjustable with respect to the back assembly.